Certain diagnostic or therapeutic procedures require the formation of a cavity in an interior body region. These cavity-forming procedures can be used to treat cortical bone which due to osteoporosis, avascular necrosis, cancer, or trauma, for example, may be fractured or prone to compression fracture or collapse and which, if not successfully treated, can lead to deformities, chronic complications, and an overall adverse impact upon the quality of life for the patient.
Vertebroplasty is where a medical-grade bone cement (such as polymethylmethacrylate, a.k.a., PMMA) is injected percutaneously via a catheter into a fractured vertebra. In this procedure, the bone cement is injected with enough pressure to enable the cement to compress and displace cancellous bone tissue. However, the direction and containment of the injected cement can be difficult to control since the space the bone cement will ultimately occupy is ill-defined, self-forming, and highly-dependent upon the internal composition of the cancellous bone in the vicinity of the injection.
To provide better bounding and control over injected bone cement, other procedures utilize devices for first forming cavities within the cancellous bone (and, accordingly, other interior body regions) prior to injecting bone cement into such a cavity. For example, some devices may utilize an expandable body or balloon that is deployed into the interior body region to form a cavity in, for example, cancellous bone tissue. These expandable body devices effectively compress and displace the cancellous bone to form an interior cavity that then receives a filling material intended to provide renewed interior structural support for cortical bone. However, the effectiveness of expandable or inflatable devices can still be negatively impacted by the internal composition of the cancellous bone in the vicinity of their use—unbeknownst to the surgeon performing the procedure because of a lack of tactile feedback—and removing the expandable or inflatable device may be difficult in certain applications of such processes.